一个封装的Ajax类

                msgbox.showmsg("数据接收完成...");
                if (x.status == 200) {
                    cmd(x.responseText);
                    msgbox.clear();
                }
                else {
                    msgbox.showmsg("请求失败," + x.statustext + "(" + x.status + ")");
                    setTimeout(msgbox.clear,3000);
                }
                return;
            }
        }
        x.open (method,url,async);
        if (method=="post") {msgbox.showmsg("正在接收数据...");x.send(postString);} else x.send();
        if (!async) {
            msgbox.showmsg("数据接收完成...");
            cmd(x.responseText);
            msgbox.clear();
        }
    }    
}